1. Field of the Invention
The present invention relates to an apparatus for feeding sheets, such as labels or covers for plastic containers, one by one from a plurality of sheets and delivering each sheet to a predetermined article.
2. Prior Art
An apparatus for sequentially feeding sheets, such as labels or covers for plastic containers, is disclosed in Japanese Patent Publication No. 55-26044.
This apparatus includes a holder for storing the covers for containers in a lapped condition. The holder is disposed above a conveyor, which transports the containers, the containers have so-called cup noodles therein. A main shaft is disposed extending between the conveyor and the holder. The main shaft is provided with a plurality of suction machines for withdrawing the covers from the holder, such that the suction machines protrude upwardly and downwardly from the main shaft.
The main shaft and suction machines operate such that the withdrawn label or cover is delivered by the main shaft synchronously to the arrival of the container on the conveyor. The holder is formed with a take-out port for exposing a front face of the cover. A plurality of claws protruding from an edge of the take-out port support the cover which is positioned at the lowest position, so that the cover does not fall from the take-out port.
Accordingly, the suction machines attract the covers, one by one, from the holder and remove the covers individually from the take-out port. When the main shaft is rotated, the cover is turned to the lower side. The cover is delivered to the container, which is transported on the conveyor.
In this feeding apparatus however, the holder of the covers is disposed such that the direction of lapping of the covers is vertical. The load applied between the claws of the holder is proportional to the amount of lapped covers contained therein. The load is therefore not constant. As a result, when the number of covers is small, the load is not great enough to allow the withdrawal by the suction machines. Conversely, when the number of covers is excessive, the friction between the cover to be withdrawn and the claws is too great. The cover cannot be released by the claws due to the friction, and the cover is not withdrawn.
Furthermore, the cover is rotated 180.degree. by the main shaft from the holder to the container positioned on the conveyor below. Thus, the operational speed of the apparatus is limited and substantial efficiency of operation is lost.
The present invention was made in view of the problems cited and it is an object of the present invention to provide an apparatus for feeding sheets to whereby predetermined articles on a conveyor, the withdrawal of the sheet from a rack by a suction machine is accomplished smoothly, improving the operational efficiency.